/*
 * Copyright (c) 2008 VMware, Inc.
 * Copyright (c) 2009 John Pritchard, WTKX Project Group
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package wtkx.wtk.effects;

import wtkx.Component;
import wtkx.wtk.Bounds;

import java.awt.AlphaComposite;
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;

/**
 * Effect that applies an opacity to a component.
 *
 * @author gbrown
 */
public class FadeEffect
    extends Object
    implements Effect
{
    private float opacity;


    public FadeEffect() {
        this(0.5f);
    }
    public FadeEffect(float opacity) {
        super();
        this.opacity = opacity;
    }

    public float getOpacity() {
        return opacity;
    }
    public void setOpacity(float opacity) {
        if (opacity < 0f || opacity > 1f)
            throw new IllegalArgumentException("opacity must be a value between 0 and 1, inclusive.");
        else 
            this.opacity = opacity;
    }
    public Graphics2D prepare(Component component, Graphics2D graphics) {
        graphics.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, opacity));
        return graphics;
    }
    public void update() {
        // No-op
    }
    public Bounds getBounds(Component component) {
        return new Bounds(0, 0, component.getWidth(), component.getHeight());
    }
    public AffineTransform getTransform(Component component) {
        return new AffineTransform();
    }
}
